Electrical and Optical Characteristics of Heterostructures Fabricated From Porous Silicon Structures Decorated with NiCo2O4 Nanoparticles by Solution Casting Method

Abstract

In this work, Nickel cobaltite (NiCo₂O₄) nanoparticles were incorporated into a porous silicon (PSi) structures prepared on silicon substrates by photoelectrochemical etching (PECE) technique. The electrical characteristics of the fabricated photodetector showed that the heterojunction of NiCo₂O₄ nanoparticles concentration of 4x10^-4 M exhibits higher photocurrent than the heterojunction of concentration of 4x10^-4 M. The optoelectronic characteristics showed that the photodetector fabricated with NiCo₂O₄ concentration of 4x10^-4 M is better than that with concentration of 4x10^-4 M. The optimum photodetector showed a responsivity of 1.22 A/W, an external quantum efficiency of 2.32, and a detectivity of 14.37×10¹⁰ Jones. The response of the fabricated photodetectors was evaluated as a function of time and found dependent on the concentration (and hence layer thickness) of the NiCo₂O₄ nanoparticles as the device fabricated with lower concentration (smaller thickness) showed faster response.